Model eye evaluation of new extended depth of focus designs versus defocus-based lenslet designs for myopia management

SIGNIFICANCE: Objective through-focus testing with phase alteration utilizing subelements technology indicates improvements in retinal image contrast across a range of retinal defocus. If validated in clinical trials, this approach may provide a better visual experience for wearers, potentially supporting compliance and myopia management outcomes. PURPOSE: This study aimed to evaluate the optical performance of modified axicons and modified light sword elements of phase alteration utilizing subelements lens design (test), compared with two defocus-based control lenslet designs, defocus incorporated multiple segments and highly aspheric lenslets using a calibrated benchtop model eye. METHODS: The through-focus optical performance of test and control lenses was evaluated. Individual subelements (Part I), and groups of elements (Part II) were assessed with 3 and 6 mm clear apertures, respectively. A Siemens star target images were captured across defocus ranging from −6.50 to +1.00 D in 0.25 D increments, repeated with 3-, 4-, and 5-mm pupils. Michelson contrast was calculated for each image and depth of focus values were obtained for spatial frequencies 15 to 22.5 cycles/degree. RESULTS: The phase alteration utilizing subelement lenses demonstrated a different depth of focus characteristics compared with both control lenses. In Part I, modified axicons (3.35 to 3.92 D) and modified light sword elements (3.32 to 3.77 D) showed a greater depth of focus across all spatial frequencies than the defocus incorporated multiple segments (p<0.05). The highly aspheric lenslets lenses showed a greater depth of focus for 15 and 17.5 cycles/degree targets (p>0.05) compared with the modified axicon. In Part II, modified axicons resulted in greater depth of focus compared with both control lenses. Similarly, modified light sword elements demonstrated a comparable or better depth of focus than both control lenses across most spatial frequencies, while both control lenses performed better with 15 and 17.5 cycles/degree targets (p<0.001). CONCLUSIONS: The model eye evaluation suggests that the phase alteration utilizing subelements spectacles can provide an extended depth of focus (EDOF) under controlled laboratory conditions, suggesting improved image contrast in front of the retina. These observations warrant further clinical investigation into visual performance and explore the potential of this technology in myopia management.